Experimental measurements of volatility in igneous systems

元素挥发性及其对温度和气相化学成分的依赖性，对于了解火山喷发、地球的组成和许多工业过程至关重要。然而，人们对高温硅酸盐熔体挥发性的化学控制知之甚少，一般都是粗略的估计。例如，对火山气体成分的直接测量必须去除估计的非挥发性尘埃成分，而行星前物质的成分是通过假设气体直接冷凝和蒸发到固体/从固体中蒸发来估计的（这是很好理解的），而不是理解不多，但物理上更现实的硅酸盐液体。不幸的是，探索后者需要我们目前还没有掌握的数据，例如在硅酸盐（岩浆）熔体上方的元素挥发性如何，以及挥发性的化学控制因素是什么。需要这些基本的化学数据来完善我们对地球历史上关键时刻的理解，例如导致月球形成的撞击。这些行星尺度的事件是使用复杂的数值模拟来模拟的，但是为了提高月球观测到的化学成分与这些模型所建议的化学成分之间的拟合度，需要对元素挥发性有更深入的了解。行星前物质的组成-类地行星的“积木”-是通过假设气体直接冷凝和蒸发到固体或从固体中冷凝和蒸发来估计的-与硅酸盐液体的冷凝和蒸发相比，这个过程相对来说是很好理解的。该项目将直接解决我们知识中的这一空白。火山学家也将受益于改进的模型，通过这些模型来了解火山气体的微量元素组成。了解影响火山气体化学的因素是解释陆地火山系统放气行为的关键。目前的方法是去除估计的非挥发性尘埃成分，可能会掩盖有关岩浆演化的重要信息，以及潜在的火山危险。鉴于许多挥发性元素的毒性，这个项目是重要的火山学家和风险/危害assessors.In这个项目中，我采取了一种新的方法来测量元素的挥发性，首先测量硅酸盐熔体中的痕量组分的属性，然后预测和测试其预期的挥发度在受控条件下。目前的目标是提供一套与行星演变、火山和环境危害直接相关的微量和痕量元素挥发物数据。

Element volatilities, and their dependence upon temperature and the chemical composition of the gas phase, are of fundamental importance to understanding volcanic emissions, the composition of the Earth and a host of industrial processes. The chemical controls on volatility from high temperature silicate melts are, however, poorly understood and crude approximations are generally made. For instance, direct measurements of volcanic gas compositions must remove an estimated non-volatile, dust component, while the compositions of pre-planetary materials are estimated by assuming that gases condense and evaporate directly to/from solids (which are well understood) rather than to poorly-understood, but physically more realistic, silicate liquids.Unfortunately, to explore the latter requires data that we currently do not posses - such as how volatile an element may be above a silicate (magmatic) melt and what the chemical controls upon volatility are. This basic chemical data is required to refine our understanding of key moments in Earth history, such as the impact that led to the formation of the Moon. These planetary scale events are modelled using complex numerical simulations, but to improve the fit between the observed chemistry of the Moon and that suggested by such models requires a deeper understanding of elemental volatility. The compositions of pre-planetary materials - the 'building blocks' of the terrestrial planets - are estimated by assuming that gases condense and evaporate directly to or from solids - a process which is, relatively, well understood compared to the condensation and evaporation from silicate liquids. This project will directly address this gap in our knowledge.Volcanologists will also benefit by having improved models by which to understand the trace element compositions of volcanic gases. Knowledge of the factors that influence volcanic gas chemistry is key to interpreting the outgassing behaviour of terrestrial volcanic systems. The current method, of removing an estimated non-volatile, dust component, may be obscuring important information concerning magma evolution, and, potentially, volcanic hazards. Given the toxicity of many of the volatile elements, this project is important to both volcanologists and risk/hazard assessors.In this project, I take a novel approach to measuring elemental volatility by firstly measuring the properties of trace components in silicate melts then predicting and testing their expected volatilities under controlled conditions. The immediate aim is to provide a data set of minor and trace element volatilities directly relevant to planetary evolution, volcanic and environmental hazards.